Advanced Mitigation of Potato Virus Y Using Bentonite-Derived Nanoclay for Viral Suppression and Enhanced Plant Defense

Potato virus Y (PVY) is a major constraint on global potato production, causing yield losses of up to 83% in Pakistan. The current study was designed to assess the antiviral efficacy of bentonite-derived nanoclay obtained from selected alluvial deposits of the Attock–Cherat Range, Pakistan, namely, Chirat Dam Deposits (L1) and Jalozai Spring Deposits (L2) in mitigating PVY infection in potato plants. The nanoclay was characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Fluorescence (XRF), X-ray Diffraction (XRD), and Cation Exchange Capacity (CEC) analysis. Characterization confirmed typical bentonite structural features, including silicate functional groups, dominant oxides (SiO₂, Al₂O₃, Fe₂O₃), and montmorillonite as the predominant mineral phase. Under a factorial glasshouse experimentation, various applications methods i.e., foliar spray (F), soil amendment (S) and combined foliar–soil treatment (F + S) at concentrations of 1% − 3% was applied prior to viral inoculation. Pre-inoculation treatments were included to assess nanoclay as a potential defense-priming agent capable of activating antioxidant pathways prior to viral challenge. Disease severity, oxidative stress markers (malondialdehyde and hydrogen peroxide), antioxidant enzymes activities (peroxidase and polyphenol oxidase), and relative PVY accumulation, as determined by DAS-ELISA, was assessed. Nanoclay treatments significantly reduced PVY symptom severity and oxidative stress while enhancing antioxidant enzyme activities. The strongest suppression of disease was observed with combined foliar and soil application at 3% applied 48 hours before inoculation. The study demonstrated that bentonite-derived nanoclay significantly reduced PVY-associated disease severity, viral accumulation (DAS-ELISA), and oxidative stress while enhancing antioxidant defense responses under greenhouse conditions.